audio: Skip libhdmipassthru on OSS builds

Change-Id: I23e25aa8e6ae63fcb40a0a1bd3bc68565527d176
diff --git a/hal/audio_extn/Android.mk b/hal/audio_extn/Android.mk
index 11bd952..f880823 100644
--- a/hal/audio_extn/Android.mk
+++ b/hal/audio_extn/Android.mk
@@ -568,6 +568,8 @@
 #-------------------------------------------
 #            Build HDMI PASSTHROUGH
 #-------------------------------------------
+ifneq ($(QCPATH),)
+
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libhdmipassthru
@@ -637,6 +639,8 @@
 endif
 include $(BUILD_SHARED_LIBRARY)
 
+endif
+
 #-------------------------------------------
 #            Build BATTERY_LISTENER
 #-------------------------------------------